What makes a lock cylinder truly secure?
Last updated: 22 April 2026
When we talk about door security, we often think of the lock, the key or even the door itself. But there is one crucial component that often goes unnoticed: the lock cylinder.
At TESA ASSA ABLOY, we know that this is where a crucial part of effective security comes into play. The cylinder is not just the part into which the key is inserted: it is the heart of the locking system and the first line of defence against attempts at tampering, extraction, breaking or unauthorised duplication.
That is why, when we talk about a truly secure cylinder, we do not focus on a single feature. We consider a range of factors that must all work together: certification, protection against lock-picking techniques, physical resistance, key-copying control, adaptability to different locking systems, and durability. This is the approach we take when developing our solutions at TESA ASSA ABLOY.
Safety isn't promised: it's proven
When it comes to security, statements alone are not enough. What matters is being able to demonstrate the level of protection each solution offers.
That is why certifications play a key role. In Europe, the EN 1303 standard assesses criteria such as strength, durability and protection against physical or tampering attacks. Achieving Grade 6 means obtaining the highest resistance rating under that standard, and demonstrates that the cylinder has passed rigorous tests.
At TESA ASSA ABLOY, we embody this philosophy in solutions such as the TX80 cylinder, designed to achieve the highest security rating, and we go even further with products such as the TK100, which far exceeds the highest level of resistance.
Protecting yourself against the most common opening techniques
A secure lock cylinder must not only lock properly; it must also be designed to withstand the most common methods used to attempt to pick it.
These include bumping and lock-picking, two techniques that continue to distinguish between a basic cylinder and one designed to offer more robust protection. At TESA, this aspect is addressed across different product ranges. Our T60 cylinder already incorporates anti-bump and anti-picking protection within the basic range; the T70 also features a specific approach to break-in resistance; and in the high-end range, our cylinders further reinforce this protection with solutions designed for more demanding installations.
This allows us to take a more realistic approach to security: not all buildings have the same requirements, but in every case the lock cylinder must be designed to withstand the type of attack it is actually likely to face.
When manipulation fails, force takes over
In addition to techniques such as bumping or lock picking, a cylinder can also be subjected to attacks such as extraction, breaking, twisting or drilling. In the face of such attacks, it is not enough for it to function properly under normal conditions: it must be able to continue providing protection precisely when someone attempts to force it open.
At TESA ASSA ABLOY, we approach security with this requirement in mind. That is why we have developed a wide range of solutions designed to withstand real-world attacks and provide reliable protection even when the cylinder is subjected to a direct break-in attempt.
Security also depends on key control
A lock cylinder may offer excellent physical resistance, but if anyone can make a copy of the key, security is compromised.
For this reason, another key aspect is the control of duplication. Cylinders with a patented key and a property card allow for more secure management of copies, restricting their reproduction to authorised centres. In the case of our patented models, copies are managed using a property card through authorised distributors and manufactured in Irun.
In addition to this, we offer Key Manager, our web-based tool that allows you to register cylinders and keys, check how many copies are in circulation, and receive notifications when a new duplicate is requested. Furthermore, for compatible models, it allows you to deactivate a lost ownership card and request a new one.
In other words, security is not just about preventing someone from forcing a door open, but also about maintaining control over legitimate access over time.
Good security should also be long-lasting
True security isn't just measured at the time of installation. It's also measured over time.
A high-quality lock cylinder must maintain its performance and level of security after thousands of opening and closing cycles. That is why durability and resistance to repeated use are key factors when assessing its reliability. At TESA, we work with solutions developed to meet the demands of intensive use, with cylinders capable of withstanding between 100,000 and 200,000 cycles, depending on the model and the application for which they are designed.
This is important because security should not be seen as a one-off measure, but rather as a form of protection that must be maintained in everyday life, whether at home, in the community or in a commercial building.
Choose wisely to protect better
Choosing a lock cylinder should not simply be a matter of selecting a component that opens and closes a door. It is a decision that directly affects the level of security, access control and the long-term reliability of the system.
At TESA ASSA ABLOY, we develop solutions designed to meet a wide range of needs, from residential properties to communal spaces and commercial projects. And as not all installations have the same requirements, we also place great importance on providing expert advice.
To this end, we have a network of distributors in whom we have complete confidence, ready to assess each individual case and help find the option that best suits each customer’s needs. Using our distributor map, any customer can easily locate their nearest outlet and receive support from a specialist.
Because a truly secure lock cylinder isn’t just one that locks a door. It’s one that meets the specific requirements of each installation, enables access control and continues to provide protection over time.
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Author: Ion Ancisar
Ion Ancisar is part of ASSA ABLOY Iberia, where he leads the business development of mechanical cylinders, drawing on more than 20 years’ experience in international industrial settings. Specialising in product strategy, portfolio management and innovation based on LEAN methodologies, he is involved in the development and implementation of solutions aimed at improving security and efficiency, particularly in contexts where a cylinder must meet not only the demands of daily use but also genuine security requirements.
